class OWNxExplorer(OWDataProjectionWidget):
...
class Warning(widget.OWWidget.Warning):
...
The base class for widget tests, WidgetTest, could include a test that first determines the widget's direct parent (OWWidgte or the base class that is derived from OWWidget), and then asserts that the widget's Error, Warning and Information are derived from base class' Error, Warning and Information.
https://github.com/biolab/orange3-network/issues/120 was caused by improper derivation of warnings:
The base class for widget tests,
WidgetTest
, could include a test that first determines the widget's direct parent (OWWidgte
or the base class that is derived fromOWWidget
), and then asserts that the widget's Error, Warning and Information are derived from base class' Error, Warning and Information.